A toroid is marked 48.5 mH. Its diameter is 15.0 cm, and its cross-sectional area is 1.8 cm². Determine its number of turns.

• A. 1.01 × 10⁶ turns
• B. 1.01 × 10⁹ turns
• C. 1.01 × 10⁴ turns
• D. 1.01 × 10³ turns

Answer: (C)